Self-sealing valve



Feb. 5, 1935.

N. sTATHAM SELF SEALING VALVE Filed Sept. 25, 1930 w d fw Patented Feb.5, 1935 UNITED STATES PATENT OFFICE 8 claims.

This invention relates to a self-sealing valve and more particularly toan automatic closure for collapsible tubes, s uch asare commonly used ascontainers for dental cream, shaving soap,

library paste, glue, etc.

sired result Without increasing the cost of the tube to a prohibitiveiigure. y

It is an object of my invention to provide a valve which may be appliedto or constructed in the outlet of a collapsible tube and which willpermit the extrusion of the contents of the tube when a pressure isapplied upon the surface of the tube but which will automatically arrestthe i flow of material through the outlet upon the release of thepressure upon the tube; Another object of the invention is to providemeans for increasing the pressure required to open a valve of this type.A further object is to provide a self-operating valve which may beeconomically constructed and applied to a collapsible tube. It is alsoan object to provide means for preventing extrusion of the material fromthe tube upon the accidental application of pressure to the container.Other objects will become apparent. The invention, in general, comprisesthe use of a diaphragm of rubber or other exible material across theoutlet of the container, which diaphragm contains a `slit or otheropening which is normally closed, but which may be opened by a pressureupon the contents of the container, to permit the extrusion' of materialfrom the container through the slit, the diaphragm having sufficientresilience to arrest the ilow of material from the container when thepressure is released. In describing the invention reference will be madeto the dra in which Figure l illustrates a fractional vertical sectionthrough the center of the upper portion of a collapsible tube embodyingmy invention. Figure 2 is a top plan View of the tube shown in Figure l.Figure 3 is a sectional view similar to Figure l, illustrating a capwhich may be applied to my improved closure. Figure 4 is a sideelevation and Figure 5 isa plan view of the cap shown in Figure 3.Figure 6 is a fractional vertical section through the center oi a tubeutilizing a modification of my invention and Figure 1 is a fractionaltop plan view of the tube shown in Figure 6. Figure 8 is a View similarto Figure 3 illustrating a modied form of the invention.

In the several figures, the numeral 1 denotes a collapsible tube of thetype customarily used as a container for dental paste, shaving soap,glue, 5 etc. The rubber diaphragm 2 is inserted Within the neck 3 of thecollapsible tube and is retained there by a shoulder 4, formed in the.neck of the tube, and a washer 5. The washer 5 may be of such dimensionsas to fit tightly within the neck 10 3 and may be forced into it underpressure before lling the tube. At the center of the rubber diaphragm 2,a slit 6 extends through the rubber at substantially right angles to thenormal surface of the diaphragm.

In using a collapsible tube embodying my improved closure, the tube isiilled in the usual manner and a pressure is applied to the lowerportion of the tube as is customary in extruding pastes and heavyliquids from collapsible tubes. 20 The pressure of the contents of thetube against the yrubber diaphragm 2 forces it outwardly and opens theslit 6 so that a strip of paste will be extruded from the tube. Uponrelease of the pressure applied to the tube the resilience of the 25diaphragm will return it to its normal position and thereby close theslit and prevent the further extrusion of the contents of the tube. Ifthe tube is used for dental paste, shaving soap, etc., any slight excessremaining upon the exterior of the 30 valve after releasing the pressuremay be removed by inserting the valve in a stream of water, since theclosed valve will prevent the water from contacting with the contents ofthe tube.

For ordinary use the rubber diaphragm would 35 be sumcient to retain thepaste within the tube. However, in transporting or packing the tube,where it is likely to be subjected to accidental pressures, it may beadvisable to apply an additional closure to prevent unintentionalextrusion 40 of the contents. This may .be accomplished by simply afxinga disc of metal or other rigid material to the outer surface of theshoulder 4 by means of a suitable adhesive. Such a disc could be appliedto the tube at the time it is nlled in -45 order that extrusion may beprevented before it is intended to initially use the tube.

If it is preferred to use a replaceable covering for this purpose, a capsimilar to that shown in Figures 3 and 8 may be supplied with the tube.50 This cap 'l may be of any suitable material and may have an edge ofresilient material which is turned down to form the rim 8. A series ofnotches 9, 9 are positioned around the rim 8 to give greater flexibilityand to permit the cap to 55 expand about the neck of the tube. Thesenotches preferably extend to beyond the bend to give the desired degreeof iiexibility. If desired, a bead or ,depression may be made in theneck of the tube with a corresponding depression or bead on the innersurface of the edge of the cap to assist in retaining the cap. The topof the cap may also have a depressed portion 9a which is shaped tocontact with the diaphragm 2 to retain it in its normal position withthe slit 6 closed. This cap may also have a handle 10 for use inapplying and removing it.

It is apparent that many other shapes and designs of closures may besubstituted for the cap?, which is shown as' illustrative of suchclosures. 'Ihe cap may also be applied to modifications of myself-sealing valve, such as thatabout to be described.

In Figures 6 and 'l I have shown a modified form of my invention inwhich the diaphragm 2a is applied across the outer edges of the neck 3aof the tube. A cap 11 is then applied to the end of the tube 'and isfastened permanently to the neck 3a 'by means of a bead 12 in the cap 11which is retained within a groove 13 in the neck 3a, or by any othersuitable means. At the center of the cap 11 there is an opening 14 whichmay be circular, rectangular or of any other desired shape. This openingis so positioned as to be opposite the slit 6a in the rubber diaphragm2a,

in order to permit the extrusion of material from the tube.

The cap 11 is so shaped as to provide a slightly convex inner surfacewhich is adapted to slightly depress the diaphragm 2a. By so depressingthe diaphragm 2a the slit 6a is pressed together at its outer edge and agreater pressure is required to expand the diaphragm sufficiently topermit the extrusion of the contents of the tube through the slit. Suchan arrangement may be preferred with a tube having a large opening orWhere a less resilient material is used.

For use in tubes of dental paste and shaving soap, I prefer to use adiaphragm of pure rubber which has been vulcanized in the usual manner,using sulphur as the vulcanizing agent. It is not intended, however, tolimit the diaphragm to this particular material, since it is apparentthat under different circumstances of use it may be desirable to usedifferent materials. For example, it may be preferred to use a metalvalve comprising ,two thin resilient plates which slightly overlap andwhich may be expanded against the resilience of the metal to provide anopening for the extrusion of the material from the tube. Other resilientmaterials may be used for this purpose but the material chosen should,of course, be one which Willnot have any harmful reaction upon thecontents of the tube.

I have found it convenient to use a rubber dia' phragm having athickness of about .030 (thirty thousandths) of an inch but thisthickness may be varied to suit the particular requirements and thematerial used. The orice in the diaphragm may be a slit of such a lengthas to give the desired width to the strip of extruded material or theopening may be in some other suitable shape which will retain thematerial within the tube until a pressure is applied to it and will thengive the -desired configuration to the extruded material. For example, ashort cross slit crossing the slit 6 or 6a may be made in the diaphragm.Such a form may particularly be applicable to a tube having a smallneck.

'I'he slight depression of the diaphragm as i1- lustrated in` Figure 6may, of course, be used in the modiiication illustrated in Figure 1 bysuitably shaping the shoulder 4 as illustrated in Figure 8. In this casethe washer 5a will retain the diaphragm 2a tightly against the shoulder4a, so that the diaphragm is held in a slightly depressed position, asillustrated in this figure. This depression may be increased or reducedto obtain the desired flexibility in the diaphragm for the particularuse to which the closure is to be applied.

It is apparent that many modifications of the invention may be used andthe particular forms illustrated are not intended as limitations of theinventions defined in the following claims.

What I claim is:

1. A self-sealing valve comprising a diaphragm yof resilient material,means for normally retaining Asaid diaphragm across the outlet of acontainer in such a position that the outer surface of the diaphragm isslightly concave, said diaphragm having an orifice which is normallyclosed but which may be opened when applying pressure to the contents ofthe tube.

2. A self-sealing valve comprising a diaphragm of resilient materialretained across the outlet of a container, said diaphragm having anorifice which is normally closed but which may be opened when applyingpressure to the contents' of the tube, and means to retain saiddiaphragm in juxtaposition to the end of the tube compriss ing a capmember having shoulders extending inwardly from the sides of the tubeand adapted to maintain the diaphragm in such a position that the outersurface is concave, said cap having an opening aligned with said orice.

3. A self-sealing valve for collapsible tubes comprising a seat formedin the neck of the tube by the metal of the tube bent inwardly, aresilient diaphragm having an aperture therein and having a diametersubstantially equal to that of the interior of the neck of the tube, awasher having an outside diameter sufficiently large to t tightly withinthe neck of the tube, said washer being forced into the neck of the tubeto retain the diaphragm against the inner surface of the seat.

4. I'he combination with a valve as defined in c1aim'3 of a removablecap, having a depressed portion adapted to` bear upon and preventoutward movement of the diaphragm.

5. A self-sealing valve comprising a diaphragm of resilient material, acontainer having an annular surface slanting inwardly and adapted toreceive said diaphragm, and means for normally retaining saidvdiaphragmacross the said outlet in such a position that the outer surface of thediaphragm is slightly concave, said diaphragm having an orifice which isnormally closed but which may be opened by applying pressure to thecontents of the tube.

6. A self-sealing valve for collapsible tubes comprising a diaphragm ofresilient material, means for normally retaining said diaphragm acrossthe outlet of a container in such a position that the outer surface isslightly concave. said diaphragm having an orifice which is normallyclosed but which may be opened by applying pressure to the contents ofthe tube, and a washer having an outside diameter sumciently large to ttightly within the neck of the tube, said washer being forced into theneck of the tube to retain the diaphragm against the inner surface ofthe first mentioned retaining means.

7. The combination with a valve as defined in claim 1 of a removable caphaving a depressed portion adapted to bear upon and prevent outwardmovement o! the diaphragm.

8. The combination with a self-sealing valve for a collapsible tube,comprising a diaphragm of 5 resilient material extending across theoutlet of the tube and having an orice which is normally closed butwhich may be opened by a pressure applied upon the contents of the tube,of a. removable cap having a depressed portion adapted to bear upon andprevent outward movement of the diaphragm.

, NOEL STATHAM.

